Heuchera plant named &#39;Delta Dawn&#39;

ABSTRACT

A new and distinct  Heuchera  plant characterized by leaves which are lime green with red to dark centers in the spring, with centers lightening with age and warmer conditions, medium large, round leaves, creamy white flowers on short flowering stems, medium, mounding habit, and good vigor.

Botanical Denomination: Heuchera hybrid

Variety Designation: ‘Delta Dawn’

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar of Heuchera and given the cultivar name of ‘Delta Dawn’. Heuchera is in the family Saxifragaceae. Heuchera ‘Delta Dawn’ originated as part of a planned breeding program for a large leaf, Heuchera villosa type with a strong central pattern that holds its color through the summer. This was a cross between Heuchera K67-1, a proprietary non-commercial hybrid, as the seed parent, and Heuchera K217-6, a proprietary non-commercial hybrid, as the pollen parent.

Compared to the seed parent, Heuchera K67-1, the new cultivar is a stronger plant with larger leaves.

Compared to the pollen parent, Heuchera K217-6, the new cultivar has red central pattern rather than an all lime colored leaf.

Compared to Heuchera ‘Miracle’ (U.S. Plant Pat. No. 20,274) or Heuchera ‘Tiramisu’ (U.S. Plant Pat. No. 20,439), the new cultivar has larger, rounder leaves, a larger habit, shorter flowering stems, and holds its red center coloration longer, never losing all of it when grown outside in Canby, Oreg.

This new Heuchera is uniquely distinguished by:

1. leaves which are lime green with red to dark centers in the spring, with centers lightening with age and warmer conditions,

2. medium large, round leaves,

3. creamy white flowers on short flowering stems,

4. medium, mounding habit,

5. and good vigor.

This new cultivar has been reproduced only by asexual propagation (tip cuttings and tissue culture). Each of the progeny exhibits identical characteristics to the original plant. Asexual propagation by cuttings and tissue culture using standard micropropagation techniques with terminal and lateral shoots, as done in Canby, Oreg., shows that the foregoing characteristics and distinctions come true to form and are established and transmitted through succeeding propagations. The present invention has not been evaluated under all possible environmental conditions. The phenotype may change with variations in environment without a change in the genotype of the plant.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a one and a half-year-old plant of Heuchera ‘Delta Dawn’ growing in a two gallon container, grown outside in late May in Canby, Oreg.

FIG. 2 shows a plant of the same age growing in the garden in mid June in Canby, Oreg.

FIG. 3 shows a six-month-old plant in bloom grown in a one gallon container in a cold greenhouse in late March in Canby, Oreg.

FIG. 4 shows a comparison of the new cultivar on the left to Heuchera ‘Miracle’ on the right. These plants are the same age and grown in one gallon containers under the same conditions in a cool greenhouse. The photo was taken in late February in Canby, Oreg.

DETAILED PLANT DESCRIPTION

The following is a detailed description of the new Heuchera cultivar based on observations taken in late June of one and a half-year-old specimens growing in two gallon containers, grown outside in Canby, Oreg. Canby is Zone 8 on the USDA Hardiness map. Temperatures range from a high of 95 degrees F. in August to an average of 32 degrees F. in January. Normal rainfall in Canby is 42.8 inches per year. The color descriptions are all based on The Royal Horticultural Society Colour Chart, 5^(th) edition.

-   Plant:     -   -   Form.—basal rosette, herbaceous perennial.         -   Hardiness.—USDA Zone 4 to 9.         -   Size.—19 cm tall from top of the foliage to the ground and             39 cm wide.         -   Habit.—mounding.         -   Vigor.—good. -   Leaf:     -   -   Type.—simple.         -   Arrangement.—rosette.         -   Shape.—broadly ovate to orbicular.         -   Lobing/division.—5 to 7 shallow lobes, shallow secondary             lobes.         -   Venation.—palmate.         -   Margins.—broadly crenate.         -   Apex.—mucronulate.         -   Base.—cordate, lobes overlapping at the base.         -   Blade size.—grows to 11.5 cm long and 11 cm wide.         -   Surface texture.—glandular pubescent on both sides.         -   Petiole description.—grows to 12 cm long and 3 mm wide,             glandular hairs, Green Yellow 1C with tints of Greyed Orange             N170C on the sunny side, Greyed Purple 187B at the very             base.         -   Leaf color.—variable depending on temperature and light,             with cooler temperatures giving deeper red colors and lower             light giving more lime than yellow tones; topside, spring             new leaves are Greyed Orange 172A with the edges Yellow             Green 151C, bottom side Yellow Green 151C with center tinted             Greyed Orange 173C; topside summer leaves Yellow Green N145A             with center and along veins Greyed Orange 175A, veins Yellow             Green 150D, bottom side Yellow Green 145B; winter leaves             topside Yellow 10A with center tinted Greyed Orange 165C. -   Inflorescence:     -   -   Size.—grows to 5 cm wide and 14 cm long.         -   Type.—thyrse.         -   Number of flowers per thyrse.—about 80.         -   Number of thyrse.—about 5.         -   Peduncle.—grows to 28 cm long and 3 mm wide at base, Yellow             Green 145A, glandular hairs.         -   Pedicel.—1.5 mm to 4 mm, with glandular hairs, Greyed Red             182B.         -   Bloom period.—occasional blooms May through October in             Canby, Oreg. -   Flower bud:     -   -   Size.—2.5 mm wide and 4 mm long.         -   Description.—glandular puberulent, ovoid, down facing.         -   Color.—Yellow Green 154C. -   Flower:     -   -   Type.—perfect.         -   Shape.—campanulate.         -   Size.—6.5 mm long and 5 mm wide.         -   Corolla description.—5 petals, 3 mm long and less than 1 mm             wide, spatulate, margins entire, tip acute, glabrous on top             and bottom side, White N155B.         -   Calyx description.—campanulate, 4.5 mm long and 3 mm wide,             with 5 lobes divided ½ way to the base, each 1.5 mm wide and             2 mm long, glandular hairs outside and glabrous inside, tip             obtuse, margin entire; color both sides Yellow Green 145C.         -   Stamen description.—5 in number, filaments 4 mm long, White             N155B, anthers 0.6 mm, Orange Red 31B, pollen Yellow Orange             23A.         -   Pistil description.—1, 2-beaked, 5 mm long and 1.5 mm wide;             ovary 1.5 mm long and 1.5 mm wide, Yellow Green 145D; style             3.5 mm long, White NN155B.         -   Fragrance.—none.         -   Lastingness.—each thyrse blooms for about 3 weeks on the             plant. -   Fruit:     -   -   Type.—two-beaked ovoid capsule.         -   Fertility.—low.         -   Color.—Greyed Brown 199C. -   Seed:     -   -   Shape.—linear.         -   Size.—2 mm long.         -   Color.—Black 202A. -   Pest and disease tolerance: Excellent disease resistance to powdery     mildew, the common problem of Heuchera. Susceptible to Heuchera rust     and root weevils. 

1. A new and distinct Heuchera plant as herein illustrated and described. 